1. Technical Field
The present invention relates to shoe construction. More specifically, the present invention relates to methods and apparatus for a shoe having a simplified construction for providing improved waterproofing capability of the shoe, a rigid counter component for keeping the heel portion firm, and for providing support to the heel of the foot and shape to the shoe, cushioning that provides both shock absorption and stability, and for eliminating insole breakdown, reducing manufacturing cost and improving efficiency.
2. Background Art
The relevant prior art is directed to methods and apparatus for constructing shoes, including the heel portion of a shoe that comprises the interface between the upper leather portion and counter component with the outsole.
There are many methods known in the prior art for constructing shoes including dress, casual and athletic shoes. Most shoes include an upper leather portion and an inner lining that cover the top of the foot, a counter placed between the upper leather portion and the lining to provide rigidity at the heel, an insole upon which the foot rests, an outsole which contacts the ground surface and possibly a filler portion that is positioned between the insole and outsole. These specific terms and others typically used in conventional or traditional shoe construction whether the shoe is stitched or glued will now be defined. The term xe2x80x9cupper leather portion or layerxe2x80x9d refers to the visibly perceivable upper external portion of the shoe. The xe2x80x9cinside liningxe2x80x9d refers to a fabric layer employed for supporting the counter component, reinforcing the upper leather portion, and providing comfort to the foot. The xe2x80x9ccounter componentxe2x80x9d refers to a piece of plastic sheet positioned between the upper leather portion and the inside fabric lining in the heel region of the shoe. The function of the xe2x80x9ccounter componentxe2x80x9d is to keep the heel firm, support the foot, and provide shape to the shoe. The xe2x80x9cmidsolexe2x80x9d refers to a piece of material such as rubber or leather that is glued to the inside fabric lining, upper leather portion, and the counter component to hold the construction together. The xe2x80x9cfillerxe2x80x9d refers to a material the serves to fill a space formed between the midsole and the outsole when the midsole is glued to the inside lining, upper leather portion and the counter component. The xe2x80x9cfillerxe2x80x9d which is glued in position can be comprised of the same material as the midsole or to the chemical compound ethylene vinyl acetate often referred to as xe2x80x9cEVAxe2x80x9d. The xe2x80x9coutsolexe2x80x9d refers to the bottom portion of the shoe that contacts the ground or floor surface which can be comprised of leather, rubber or any of several suitable synthetic materials. The outsole is typically glued to the xe2x80x9cfillerxe2x80x9d. The xe2x80x9cforepartxe2x80x9d refers to that portion of the shoe or sole forward of the heel. The xe2x80x9clastxe2x80x9d refers to a form or mold which simulates the shape of a foot and which is employed to shape and size a shoe.
One of the several methods of shoe construction known in the art is referred to as the side stitch method. In the side stitch method, the upper leather portion, inner lining and counter components of the shoe and the outsole are machine stitched together along a side interface thereof. In some cases, cement may also be used to help secure the insole and inner lining to the outsole. After joining the upper leather portion and the outsole, the stitching remains visible along the side of the shoe. The side stitch method of shoe construction is often employed in outdoorsman and workman type shoes. A second method of shoe construction includes exclusively a cementing process (i.e., no stitching) in which the bottom of the upper leather portion and the outsole of the shoe are machine glued and pressed tegether. Typically, the upper leather and inner lining layers (and possibly a filler layer) are cemented between an insole and an outsole. The cementing method of shoe construction is commonly utilized for athletic footwear.
A third method of shoe construction known in the prior art is the xe2x80x9cslip lastedxe2x80x9d method. In the xe2x80x9cslip lastedxe2x80x9d method, the upper leather portion and the outsole are vertically machine stitched together all the way around the shoe. The outsole may have vertical slots formed in the bottom thereof so that the vertical stitching can pass through the upper leather portion and through that portion of the outsole positioned above the vertical slots. The xe2x80x9cslip lastedxe2x80x9d method is often used for oil tan leather shoes (such as moccasins) which cannot be glued because of the oil tan treatment applied to the leather.
A fourth method of shoe construction is identified as the xe2x80x9cstitch and turnxe2x80x9d method. In the xe2x80x9cstitch and turnxe2x80x9d method, the upper leather portion is stitched to the outsole on the side of the shoe. The outsole is typically a single molded unit and the upper leather portion is machine stitched thereto in a known manner. During initial construction, the stitching is accomplished in such a manner that the smooth or top side of the upper leather portion is facing downward and the rough side of the leather is facing upward when the upper leather portion is extended outward from the side of the shoe. After the upper leather portion has been stitched to the side of the outsole, it is turned over the top of the outsole so that the smooth side of the upper leather portion is reversed and faces upward, i.e., exterior, as in a finished shoe. However, the rough side of the leather then faces downward, i.e., toward the interior part of the shoe.
Many problems exist with conventional or traditional shoe construction of the prior art. For example, if the side stitch method is employed to construct the shoe, it is not possible to incorporate a firm counter component therein. This is because the firmness or stiffness of the counter component prevents the successful side stitching of the shoe by the stitching machinery. Further, use of the side stitching method of construction prevents proper waterproofing of the shoe at the interface of the upper leather portion and the outsole. The waterproofing problem exists because the machine stitch holes pass completely through each layer of shoe material, i.e., upper leather portion, counter component and inside lining, and thus cannot prevent the entry of moisture. The problems associated with the inability to provide a firm counter component and proper waterproofing of the shoe also exist with the xe2x80x9cslip-lastedxe2x80x9d and xe2x80x9cstitch and turnxe2x80x9d methods of shoe construction.
One prior art method of providing a firm counter component was to stitch the upper leather portion, counter component and inside fabric lining to the midsole. Thereafter, the midsole, filler and outsole were glued together. Waterproofing of the shoe could be achieved in this manner but this prior art method was time consuming and expensive. In an alternative prior art method, the counter component was installed between the upper leather portion and the inside fabric lining typically from above the shoe. The top ends of the upper leather portion and inside fabric lining were stitched together while the bottom ends were cemented to the bottom of the midsole. Then, the bottom of the midsole was glued to the outsole with the filler in between. In addition to bonding the components together, the cement also served as a means for closing the machine stitch holes. This assembly procedure required several steps and was time consuming and expensive because mistakes were common. Further, cemented components often separate after being successfully bonded together, for example, the separation of the upper leather portion from the outsole.
Another problem that exists in prior art methods of manufacturing shoes occurs, for example, with xe2x80x9cstitch and turnxe2x80x9d construction. In the xe2x80x9cstitch and turnxe2x80x9d shoe construction method, the insole sits on top of the outsole wall. The insole is typically comprised of soft material, . However, the outsole wall is comprised of hard material and is cube-shaped. Thus the corners of the outsole wall form 90 degree angles. Further, the insole is wider than the outsole wall and thus the ends of the insole extend past the corners of the outsole wall. When body weight is applied to the top of the insole via the foot, pressure is applied to those portions of the insole resting on and extending over the corners of the outsole wall. Consequently, the insole would break resulting in discomfort to the bottom of the wearer""s foot. In an effort to overcome this problem, the thickness of the insole was increased to prevent the breakage. However, this solution reduced the available volume in the toe box of the shoe creating a fitting problem. Thus, the volume of the toe box had to be increased to solve the fitting problem. Unfortunately, increasing the volume of the toe box caused the shoe to become less attractive and unacceptable to consumers.
A traditional method of constructing shoes in the prior art is as follows. Initially, the upper leather portion was cut from leather parts and stitched together to form the style of shoe desired. Then, the upper leather portion was loosely placed over a xe2x80x9clastxe2x80x9d where the xe2x80x9clastxe2x80x9d is a model of the foot size for which the shoe is being constructed. Then a suitably sized midsole was placed underneath the xe2x80x9clastxe2x80x9d. Thereafter, the upper leather portion was secured to the midsole by wrapping a small dimension of the leather of the upper leather portion underneath the midsole. This wrapping of the upper leather portion underneath the midsole was performed around the entire circumference of the midsole creating a ring of upper leather on the bottom of the midsole normally referred to as a xe2x80x9cleather allowancexe2x80x9d. The ring of leather necessarily wrinkled at the toe and heel sections. At this point, the upper leather portion and the midsole with the ring of leather underneath were placed in a xe2x80x9ctoe lastingxe2x80x9d machine to form the shape of the toe of the shoe. The ring of leather was then manually cemented to the bottom of the midsole.
The filler was utilized to fill the space formed between the midsole and the outsole caused by the ring of leather wrapped and cemented underneath the midsole. Thus, one function of the filler was to make the bottom of the shoe construction flat. The surface of the ring of leather underneath the midsole was roughened by sandpaper before additional cement was applied to attach the ring of leather to the midsole and the filler to ensure adequate bonding. After the ring of leather was cemented to the midsole and the filler, the bottom of the combined upper leather portion, midsole and filler was now a flat surface. The bottom flat surface of the combined upper leather portion, midsole and filler was then sanded in preparation to be mated and cemented with the top surface of an outsole. Additionally, the top surface of the outsole was also roughened as with sandpaper. An adhesive was then applied to the bottom flat surface (formed by the ring of leather, midsole and filler on the bottom of the upper leather portion) and also to the top surface of the outsole. The bottom flat surface of the upper leather portion was then mated with the top surface of the outsole. The entire shoe construction was then exposed to a heated environment to accelerate the bonding of the adhesive to the leather. The shoe was then placed into a foot-shaped holder and was subjected to a press that applied pressure to the top, bottom and sides of the shoe for a short period of time. The shoe was then permitted to sit so that the adhesive would cure.
In an alternative method, side stitch construction could be substituted for the cementing process. However, in the side stitch construction, the upper leather portion, counter component and the inner lining layer are each stitched together by the stitching machinery. This situation results in creating holes through each of the layers of the shoe construction. Consequently, because of the machine stitch holes, waterproofing of the shoe becomes a major problem.
Thus, there is a need in the art for a shoe having a simplified construction which provides an improved waterproofing capability by eliminating machine stitch holes that penetrate all of the layers of the shoe construction and which seals existing machine stitch holes with a waterproofing medium, and which eliminates breakage of the insole component, and which provides a firm heel portion by utilizing a rigid counter component installed between an upper leather layer and an inner lining layer, and provides shape to the shoe and structure that exhibits both shock absorption and stability, and which reduces manufacturing cost and production time and improves efficiency.
Briefly, and in general terms, the present invention provides a new and improved shoe having a simplified construction wherein the simplified construction can be employed for many different shoe designs including dress, casual and athletic shoes. The novel and non-obvious shoe having simplified construction exhibits an improved waterproofing capability by eliminating machine stitch holes that penetrate all of the layers of the shoe construction and by sealing existing machine stitch holes with a waterproofing medium, and which eliminates breakage of the insole component, and which provides a firm heel portion by utilizing a rigid counter component installed between an upper leather layer and an inner lining layer, and provides shape to the shoe and cushioning that provides both shock absorption and stability, while simultaneously reducing manufacturing cost and production time, and improving efficiency.
In a preferred embodiment, the inventive shoe having a simplified construction includes an upper leather layer having a top or upper edge and a bottom or lower edge. The upper leather layer is an outer layer and functions to enclose a foot of the individual wearing the shoe. An inner lining layer is positioned on the inside surface of the upper leather layer to provide support to the shoe and comfort to the foot. The inner lining layer is typically comprised of a synthetic material but can also be fashioned from leather. The inner lining layer is joined to the top or upper edge of the upper leather layer as by stitching. Thus, a pocket or gap exists between the inner lining layer and the upper leather layer. In order to provide a stiff heel section to the shoe, a rigid counter component typically comprised of plastic is positioned within the pocket or gap formed between the upper leather layer and the inner lining layer.
An outsole wall, which is typically U-shaped in the heel of the shoe and may extend around the entire perimeter of the shoe, interfaces with the upper leather layer. The outsole wall includes an upward extending top portion that is joined to the upper leather layer typically by stitching. The inner lining layer and the rigid counter component are not stitched to the outsole wall. The outsole wall includes a slanted inner surface in the heel portion of the shoe which forms a cavity that is shaped in the form of an inverted frustum. The outsole wall is comprised of a high density material such as hard rubber to provide stability to the structure of the shoe.
An insole is provided which functions to support the foot. The insole is shaped in the form of an inverted frustum, i.e., in the shape of an inverted cone having a flat top surface in lieu of a pointed apex. Thus, the insole includes a slanted outer surface that cooperates with the slanted inner surface of the outsole wall. Consequently, the inverted frustum-shaped insole is conveniently received into the inverted frustum-shaped cavity formed in the center of the outsole wall at the heel of the shoe. The insole is fashioned from a low density material such as soft rubber for providing shock absorption for improving the comfort of the shoe. An outsole typically comprised of high density material such as hard rubber is joined as by an adhesive to the bottom of both the outsole wall and the insole for completing the shoe construction and for contacting the ground surface.
The present invention is generally directed to a shoe having a simplified construction which is very versatile and can be employed for many different shoe designs. The simplified construction offers stability and shock absorption to the foot, improves waterproofing characteristics, and eliminates breakage of the insole component. In its most fundamental embodiment, the shoe having a simplified construction includes an upper layer having a top edge and a bottom edge for enclosing a foot in a shoe. An inner lining layer is joined to the top edge of the upper layer for providing comfort to the foot. A counter component is positioned between the upper layer and the inner lining layer for supporting a heel of the shoe. An outsole wall having a slanted inner surface forms a cavity within the outsole wall. Further, the outsole wall is joined to the bottom edge of the upper layer. An insole for supporting the foot is shaped to include a slanted outer surface so that the insole fits within the cavity formed within the outsole wall. Finally, an outsole is joined to a bottom of the outsole wall and the insole for contacting a ground surface.
In an alternative embodiment, the construction of the upper layer, inner lining layer and rigid counter component are identical to that of the preferred embodiment. However, in the alternative embodiment, an outsole wall is employed that includes a vertical inner surface for forming a cavity. The outsole wall is also joined to a bottom edge of the upper layer as by stitching. The cavity is rectangular-shaped and accommodates a rectangular-shaped midsole filler layer. An insole which is employed to support the foot is joined to a top surface of the midsole filler layer as with an adhesive. An outsole comprised of a high density material such as hard rubber is joined to the bottom of the outsole wall and the midsole filler layer as with an adhesive. The outsole is employed for completing the construction and making contact with the ground surface.
These and other objects and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings which illustrate the invention, by way of example.